December 2024 ESRFnews

15

CONNECTOMICS

the BM18 beamline, the international Human Organ

Atlas project is already imaging human organs at sub-

micron resolution; XNH at ID16A can extend this into

the nano realm, depicting not just individual neurons

but also their connections, or synapses, as well as their

internal nuclei and other organelles (see right).

Meanwhile, collaborators at the Francis Crick

Institute in London, UK, are using visible light

microscopy to determine which regions of the brains

of living mice light up in response to different stimuli.

Once they know the regions of interest, they can

investigate them in sub-cellular detail with XNH;

preliminary results depict the different neural networks

that appear when the mice smell apples or bananas. A

similar approach is being taken in a collaboration with

the University of Melbourne, in this case to contrast

the neural networks in normal brains with those in

brains affected by autism spectrum disorder Here the

brains studied are in fish which can be given a genetic

mutation to effect a physiology similar to that present

in autism

In the scheme of lifesciences instrumentation XNH

is still new After decades committed to MRI and EM

however it is clear that researchers are beginning to

embrace it And their expectations can only rise in

recent months the ESRF has received strong support

from the user community and its Scientific Advisory

Committee for the construction of a new beamline

on the ID18 port for nanoimaging in the life sciences

and biomedicine where connectomics investigations

will be able to flourish Just a few years ago we could

only explore neural circuits in minuscule regions of

the brain smaller than the size of a poppy seed says

Pacureanu This is equivalent to living in a little village

disconnected from the rest of the world The EBS at

the ESRF together with the capabilities of the nano

imaging beamline are bringing about a revolution in

the field of connectomics

Above: Alexandra

Pacureanu

believes a new

technique on the

ID16A beamline,

X-ray holographic

nano-tomography,

can reconstruct

complete

“connectomes”

of the neurons in

animal brains.

Jon Cartwright

E S R F/ S T E F C A N D É

Above: A volume rendering of the body of a neuron by XNH.

Within the cells membrane it is possible to see the nucleus

alongside smaller individual structures known as nucleoli

E S R F/ A. P A C U R E A N U